ACT stands for American College Testing. It is one of the standardized tests that many students take in order to assess and show colleges their skill level.
The ACT consists of 4 sections: English, Math, Reading, and Science, each given a score from 1 (worst) to 36 (best).
Your final score will be an average of all 4 of your scores, again from 1 to 36. The average ACT score is a 19.